MEXICO CITY (Reuters) - Possessing marijuana, cocaine and even heroin will
no longer be a crime in Mexico if they are in small amounts for personal
use under new reforms passed by Congress that quickly drew U.S. criticism.

The measure given final passage 53-26
by senators in a late night session on Thursday is aimed at letting police
focus on their battle against major drug dealers, and President Vicente
Fox is expected to sign it into law.

"This law provides more judicial
tools for authorities to fight crime," presidential spokesman Ruben
Aguilar said on Friday.

He said the reforms, which were proposed
by the government and approved earlier this week by the lower house of
Congress, made laws against major traffickers "more severe."

The legislation came as a shock to Washington,
which counts on Mexico's support in its war against drug smuggling gangs
who move massive quantities of cocaine, heroin, marijuana and methamphetamines
through Mexico to U.S. consumers.

"I would say any law that decriminalizes
dangerous drugs is not very helpful," said Judith Bryan, spokeswoman
for the U.S. Embassy in Mexico City. "Drugs are dangerous. We don't
think it is the appropriate way to go."

She said U.S. officials were still studying
the reforms, under which police will not penalize people for possessing
up to 5 grams of marijuana, 5 grams of opium, 25 milligrams of heroin or
500 milligrams of cocaine.

People caught with larger quantities
of drugs will be treated as narcotics dealers and face increased jail terms
under the plan.

The legal changes will also decriminalize
the possession of limited quantities of other drugs, including LSD, hallucinogenic
mushrooms, amphetamines and peyote -- a psychotropic cactus found in Mexico's
northern deserts.

Fox has been seen as a loyal ally of
the United States in the war on drugs, but the reforms could create new
tensions.

A delegation from the U.S. House of Representatives
visited Mexico last week and met with senior officials to discuss drug
control issues, but was told nothing of the planned legislative changes,
said Michelle Gress, a House subcommittee counsel who was part of the visiting
team. "We were not informed," she said.

HARDENED CRIMINALS

Hundreds of people, including many police
officers, have been killed in Mexico in the past year as drug cartels battle
for control of lucrative smuggling routes into the United States.

The violence has raged mostly in northern
Mexico but in recent months has spread south to cities like vacation resort
Acapulco.

Under current law, it is up to local
judges and police to decide on a case-by-case basis whether people should
be prosecuted for possessing small quantities of drugs, a source at the
Senate's health commission told Reuters.

"The object of this law is to not
put consumers in jail, but rather those who sell and poison," said
Senator Jorge Zermeno of the ruling National Action Party.

Hector Michel Camarena, an opposition
senator from the Institutional Revolutionary Party, warned that although
well intentioned, the law may go too far.

"There are serious questions we
have to carefully analyse so that through our spirit of fighting drug dealing,
we don't end up legalizing," he said. "We have to get rid of
the concept of the (drug) consumer."